Envelope folding machine

ABSTRACT

An envelope, which is to be folded, is delivered off an endless belt to a set of gripping bars disposed around the periphery of a rotating drum. The gripping bars carry the envelope under a rotating scoring roller which scores the envelope along as many lines, spaced longitudinally of the envelope, as there are folds to be made in the envelope. As the drum revolves, successive portions of the envelope are released by the gripping bars, so that these successive portions bend away from the body of the envelope along the score lines by their inherent resiliency. As each successive portion of the envelope is released, a paddle is advanced toward the drum to engage the released portion and bend it down onto the yet-unreleased part of the envelope to effect a fold. There are as many paddles or deflectors disposed about the drum as there are folds to be made in the envelope. Thus as the drum rotates the envelope is folded into the desired small compass.

United States Patent Inventors Gerald A. Taylor Bergen; George F.Wadleigh, Brighton, N.Y. App]. No. 800,378 Filed Feb. 19, 1969 PatentedFeb. 23, 1971 Assignee Rochester Envelope Company Rochester, N.Y.

ENVELOPE FOLDING MACHINE Primary Examiner-Bernard Stickney Attorney B.Edward Shlesinger ABSTRACT: An envelope, which is to be folded, isdelivered ofi' an endless belt to a set of gripping bars disposed aroundthe periphery of a rotating drum. The gripping bars carry the envelopeunder a rotating scoring roller which scores the envelope along as manylines, spaced longitudinally of the envelope, as there are folds to bemade in the envelope. As the drum revolves, successive portions of theenvelope are released by the gripping bars, so that these successiveportions bend away from the body of the envelope along the score linesby their inherent resiliency. As each successive portion of the envelopeis released, a paddle is advanced toward the drum to engage the releasedportion and bend it down onto the yet-unreleased part of the envelope toeffect a fold. There are as manypaddles or deflectors disposed about thedrum as there are folds to be made in the envelope. Thus as the drumrotates the envelope is folded into the desired small compass.

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INVENTORS GERALD 'A. TAYLOR GEORGE F. WADLEIGH flTORNEY PATENTEI]P55231971 3564.982

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- INVENTORS FIG. l5 GERALD A. TAYLOR W5 GEORGE E WADLEIGH J LTTORNEYENVELOPE FOLDING MACHINE The present invention relates to machines forfolding envelopes, and more particularly to machines for foldingenvelopes used in mailing exposed photographic film to processors fordevelopment and printing.

Until relatively recently, cloth sacks were used for mailing exposedfilm rolls to the processor. When a person bought a roll of film, he wassupplied with the cloth sack for mailing the roll to the processor afterthe roll had been exposed. There was a tag attached to the sack bearingthe name and address of the processor, and on which the photographermight put his own return address.

Because cloth sacks are expensive, paper envelopes have come more andmore into use as substitutes for cloth sacks. One problem with paperenvelopes, however, has been to fold them within small enough a compassto go into the box or carton in which the roll of film itself is packedfor sale. For the paper envelopes to be practical, they must be foldedinto the desired compass at high speed.

The primary object of the present invention is to provide a machinewhich will fold paper envelopes of the character described into thedesired compass at higher speed than prior such machines for thispurpose.

Another object of the invention is to provide a machine of the characterdescribed which will be more compact, and require less space.

Another object of the invention is to provide a machine of the characterdescribed which can readily be adapted for folding envelopes of varioussizes.

Other objects of the invention will be apparent hereinafter from thespecification and from the recital of the appended claims, particularlywhen read in conjunction with the accompanying drawings.

In the drawings:

FIG. 1 is a fragmentary side elevation showing somewhat diagrammaticallya machine built according to one embodimerit of this invention;

FIG. 2 is a fragmentary plan view of this machine;

FIG. 3 is a detail view showing in elevation the type of grips forgrasping the envelope blank as it is fed into the machine;

FIG. 4 is a section on the line 4-4 of FIG. 3 showing one such grip inerect, open position;

FIG. 5 is a view similar to FIG. 4 but showing the gripper pivoted tooperative position;

FIG. 6 is a fragmentary detail view showing gripping position one of theother type grippers used in a set for holding the envelope duringfolding;

FIG. 7 is a fragmentary view showing one of these latter type grippersmoved to released position;

FIG. 8 to 12 inclusive are fragmentary views illustrating somewhatdiagrammatically successive steps in the folding of an envelope on theillustrated machine;

FIG. 13 is a more or less diagrammatic view illustrating the drive tothe several illustrated parts of the machine;

FIG. 14 is a rear view of an envelope such as may be folded in a machinebuilt according to the present invention; and

FIG. 15 is a view showing the envelope after folding.

Referring now to the drawings by numerals of reference, 15 (FIG. 14)denotes one type of envelope which may be folded on the machine. It ismade from a single sheet of paper folded upon itself to provide a front16, two rear flaps 17 and 18, a bottom flap 19, which is folded over thebottoms of the rear flaps, and glued thereto, and a top flap 20, whichis adapted to be fastened over the rear flaps by a conventional wingedfastener 21 that is riveted to one of the rear flaps, and that isadapted to be passed through the hole 22 in a pasteboard grommet 23 andin the top flap to secure the top flap in closed position. The grommetis glued to the back of the top flap 20.

The envelopes E, which are to be folded, are delivered one by one from ahopper or other supply source (not shown) onto an endless belt 30(FIG. 1) with their bottom ends forward.

The belt 30 travels between the two parallel rails 32 (FIG. 2) of aguide member 33 which is suitably supported on the frame of the machine,and which extends to the vicinity of a drum 34.

Drum 34 is mounted on it a plurality of gripper bars which hold anenvelope initially, and then release different parts of the envelopestep-by-step progressively to permit the folding operation to beeffected. The gripper bars are arranged, in the machine illustrated, intwo sets spaced angularly from one another so that two envelopes E canbe folded simultaneously as the drum revolves, carrying them through themachine.

In the machine shown, in each set of gripper bars there are four gripperbars 36 (FIGS. 1, 6 and 7) and one gripper bar (FIGS. 1, 3, 4 and 5).Each gripper bar 36 has pivotally mounted on it two opposed,laterally-spaced levers 38 and 39 (FIG 6). These two levers are pivotedby means of pins 41 on the associated bar 36. Each lever carries agripping finger 42 that, when in operative position, extends over thetop of its bar 36 in position to engage and hold against the bar anenvelope 15 (E). The two fingers 42 of a pair engage the envelope atopposite lateral sides thereof.

Each lever 38, 39 is forked to straddle a shaft 44 that is journaled atopposite ends in the associate bar 36. Each lever is mounted to pivot ina recess 45 in the bar, and is normally urged to released position by acoil spring 46 that is interposed between one end wall of a recess 45and the confronting side of the associated lever 38 or 39. Each levercarries a roller follower 48 that is adapted to engage a cam member 50which is keyed or otherwise secured to the shaft 44 to rotate therewith.The cam member 50 is so shaped that when the shaft 44 is rotatedangularly from the position shown in FIG. 6 to that of FIG. 7, forinstance, the springs 46 will rock the levers 38 and 39 associated withthe shaft to move the gripping fingers 42 upwardly to move them toreleased positions out of engagement with the envelope resting on theassociated bar.

In the embodiment of the invention shown, there are, as previouslystated, two sets of grippers mounted on the drum 34. Each set consistsof four grippers bars 36 and a gripper bar 70. The bars 70 precede thebars 36 of each set in the direction of rotation of the drum. Each bar70 (FIG. 3) supports rotatably a shaft 72, which is joumaled in thegripper bar 70, and which carries two gripper members 74. Each member74, as shown in FIG. 3, is generally T-shaped in elevation and carriesat its top an elongate gripper portion 76 that is of generally invertedU-shape in cross section and extends longitudinally along and over theassociated bar 70.

FIG. 4 shows a gripper 74 in released position. FIG. 5 shows thisgripper in gripping position to clamp an envelope against the plane topsurface of the associated bar 70.

The envelopes are delivered from the belt 30 into a pair of grippers 74at the proper time in the cycle of operation of the machine, that is, asa bar 70 rotates with drum 34 into position adjacent delivery belt 30(FIG. 1). At this time the grippers 74 of a set will be in their openpositions (FIG. 4) to receive an envelope and to limit the extent offeed of an envelope into the machine. The portion 77 (FIG. 4) of agripper 70 acts as a stop.

Delivery is timed by two spaced gate members 52 (FIG. 1), which arecarried by two parallel, spaced lever arms 54 that are secured to ashaft 56. The members 52 move in the space between guide member 33 andthe confronting portion of belt 30, as shown in FIG. 2. When the members52 are in the position shown in FIG. 1, an envelope isfree to pass offbelt 30 into an open pair of gripper jaws 70. When the gate members 52are raised to their upper positions they stop envelopes from moving offconveyor belt 30 into a pair of gripper jaws 70.

The movements of the gate members 52 are controlled by a cam 62 and afollower 60. Secured to shaft 56 at one end thereof is a lever arm 58that carries the roller follower 60 (FIGS. 1 and 2) which is adapted toride on the periphery of the cam 62. Cam 62 is secured to a shaft 64.This shaft also carries two members 66 (FIG. 2) which overlie the belt30 and have segmental enlarged diameter portions 67 (FIG. 1) thatcooperate with a disc 31 to feed each envelope, at the correct time, offthe belt 30 into the opened grippers of the bar 70 which are thejuxtaposed to belt 30.

Disposed above the drum 34 is a second rotary drum 80. This drum carriesaround its periphery a plurality of scoring blades 82 which projectradially from drum 80. There are as many blades 82 as there are folds tobe made in the envelope.

There are also as many gripping bars 36 in each set thereof as there arescore lines in the envelope.

The various grippers are actuated by stationary cams 90, 91, 92, 93, 94(FIG. 2), respectively, that are fixed to a sleeve 165 which is formedwith a flange 166 by which it is fastened to the machine frame 167.These earns 90, 91, 92, 93, 94 engage followers 100, 101, 102, 103, and104, to operate the grippers 42, 74 through rotation of the severalshafts 44 and 72 carried by the bars 36 and 70.

The earns 90, 91, 92, 93, 94 are shaped so that just before each set ofgrippers reachesthe top position in FIG. 1, and after apreviously-folded envelope has been delivered onto a conveyor belt 170to be carried away, all the gripper bars are opened so as to receive anew envelope from belt 30, and then the set of grippers is closed on thenew envelope and then the individual grippers of the set releasesuccessively as drum 34 rotates to permit folding the envelope.

The folding operations themselves are effected by operation of paddles110, 112, 114, and 116, which are operated by cams 120, 122, 124, and126 (FIG. 2) respectively, that are secured to the shaft 95 coaxial withthe drum 34 but at the opposite end of the drum from the stationaryearns 90, 91, 92, 93,94.

Each paddle or folding member, such as that shown at 112 in FIG. 2,comprises two thin plates 134 that have concave surfaces 136 (FIG. 1) attheir free, outer ends, and that are fixedly secured in a bar 138. Eachbar 138 is secured to a rod 140 that is slidable in a housing 142 whichis fastened by a bracket 144 to the frame of the machine. A coil spring146, which surrounds each rod 140, and which is interposed between oneend wall of the associated housing 142 and a washer-nut combination 148tends to move each paddle 134 in one direction to its outward position.A nut 150 threaded on each rod 140 limits the outward movement of thecorresponding rod.

Each rod 140 is moved to its forward position by a forked member 152(FIG. 1), which straddles the associated rod 140 and carries rollers 154which engage behind the bar 138. Each yoke 152 is secured to a shaft 156to which there is secured an arm 158 which carries a roller 160 thatengages the periphery of the associated cam 120, 122, 124, or 126. Eachshaft 156 is journaled in a bearing member 162 that is carried by theassociated bracket 144.

In the operation of the machine, theenvelope, which is to be folded, isdelivered off belt 30 by the gate or stop 52 (FIG. 1) and slides overguide member 33 into engagement with the jaws 74 (FIGS. 3, 4, of thatone of the two gripper bars 70 that at that time is carried by drum 34into position to engage the envelope. In FIG. 1, the gripper bar 70 atthe right in the then lower set of gripper bars, is shown rotatingupwardly to a position for gripping an envelope that is to be fed off ofbelt 30, while the bar 70 in the then upper set of gripper bars hasalready released an envelope E which is still clamped, however, by thegripping fingers of the bars 36 of this upper set.

As each envelope is fed off of belt it enters the jaws 74 of the gripperbar 70 then in position to receive it. As the drum 34 revolves, theroller 100 (FIG. 2), associated with this gripper bar, rolling on thecam 90 rocks shaft 72 (FIGS. 3, 4 and 5) in a direction to swing thejaws 74 of this bar from the position shown in FIG. 4 to that shown inFIG. 5, thereby to grip the envelope adjacent its bottom edge.

As the first of the following gripping bars 36 comes abreast of theenvelope, the roller 101 (FIG. 2) associated with that bar, rolling oncam 91 causes the shaft 44 (FIGS. 6 and 7) associated with that bar torock first in one direction to swing the associated gripping fingers 42open, as shown in FIG. 7, to allow the envelope to pass beneath them;and then the roller rides down on the cam 91, causing the shaft 44 torock in the opposite direction to move the associated fingers 42 toclamping position as shown in FIG. 6 to clamp the envelope against theassociated bar 36.

As the succeeding bars 36 come abreast of the envelope, the rollers 102,103, 104 riding on their respective cams 92, 93, 94 first open thefingers 42 associated with the respective bar so that the envelope canfeed under these fingers and then close these fingers on the envelope toclamp the envelope against the respective bar.

As the drum continues to rotate, the envelope, which is now gripped bythe jaws 74 of bar 70 and by the gripping fingers 42 of the four bars 36of the group is carried by drum 34 beneath the successive scoring bladesof the rotating drum (FIG. 1).

The blades 82 of the rotating drum 80 impress parallel'score lines onthe envelope that are spaced from one another lengthwise of theenvelope. These are the lines on which successive folds are to be madein the envelope.

The now-scored envelope, still gripped by jaws 74 and fingers 42, isthen carried by drum 34 toward the first paddle 110. As it approachesthis paddle, cam (FIG. 2) through roller and associated shaft72 (FIG. 3)causes the jaws 74 of the associated bar 70 to be released (rocked fromthe position of FIG. 5 to that of FIG. 4), allowing the bottom portionof the envelope to raise up along its first score line, as shown inFIG. 1. The paddle propelled by associated fork 152 through operation ofcam and associated lever 158 is projected in front of this slightlyraised bottom portion of the envelope 167 (FIG. 1) to intercept theleading (bottom) edge of the envelope. After the leading edge of theenvelope slides on the paddle face a short distance, the cam 120releases the paddle and the paddle moves rapidly outward under actuationof the associated return spring 146 to the position shown in FIG. 8 sothat as the drum continues to rotate part 167 of the envelope can passunder this paddle as shown in FIG. 8 and be folded down into the mainbody of the envelope which is still gripped by the gripping fingers 42of the several bars 36 of the roup.

Cam 122 (FIGS. 1 and 2) then causes paddle 112 to move forward to theposition shown in FIG. 8 so that it will be so disposed as to engageunder the now-leading portion of the envelope at the first fold.

As the drum 34 continues to rotate and the first of the gripping bars 36approaches the paddle 112, the fingers of this gripping bar are releasedby action ofcam 91 (FIG. 2) and follower 101 associated with this barand the released section of the envelope rising about the next scoreline on the envelope is engaged by the paddle 112. As the drum continuesto revolve, this newly-released portion of the envelope is caught on theleading edge of the paddle 112, and is bent upwardly successively to thepositions shown in FIGS. 9 and 10, respectively.-

The roller associated with paddle 112 now rides down on a low spot ofcam 122 allowing associate spring 146 to withdraw this paddle to theposition shown in FIG. 11. At the same time paddle 110 is again actuatedforward so that its trailing edge comes under the leading edge of paddle112. This actually tucks the folded portion into the fold being formed.This tucking action results from the angular placement of paddles' 110and 112. As the drum continues to revolve, the folded portion 167-168 ofthe envelope rides on the leading edge of paddle 112 and is carriedunder paddle 112 and is flattened against the rest of the envelope.

As the drum 34 continues to revolve, the fingers 42 of the secondgripping bar 36 of the set are released by action of cam 92 (FIG. 2),associated roller 102 and associated shaft 44, and paddle 114 is movedto operative position by action of the cam 124, associate roller 160,and shaft 156. The newlyreleased part 169 of the'envelope rises aboutthe third score line; and as the drum 34 revolves, the leading end ofthe paddle 114 engages this section 169 of the envelope while the paddle112 holds the now folded section 168.

The roller 160 associated with paddle 112 now rides down on a low spotof cam 122 allowing the associated spring 146 to retract this paddle;and as the drum continues to rotate the folded portion of the envelopeis carried under paddle I14 and flattened against the rest of theenvelope, as shown in FIG. 12, in a manner similar to that described forsection 18 of the envelope.

As the drum 34 continues to rotate, the fingers 42 of the third bar 36of the group are moved to released position by cam 93 (FIG. 2),releasing the next section 171 (FIG. 1) of the envelope so that it risesabout the fourth score line, through its own resiliency. Paddle 116 isprojected into position to engage this newly-released section of theenvelope, by operation of cam 126 (FIG. 1), associated roller 160 andshaft 156. While the paddle 114 is still holding fold 169 of theenvelope, paddle 116 engages section 171 of the envelope, raising thisportion up as shown in FIG. 1.

The roller 160 associated with paddle 114 now rides down on a low spotof cam 124, allowing the associated spring 146 to retract this paddle;and as the drum continues to rotate the folded portion of the enveloperides under paddle 116 and is flattened against the remaining portion ofthe envelope, completing the folding operation.

After the folded envelope passes the paddle 116, and the clamping member42 (FIG. 6) on the last gripper bar 36 of the group are released byaction of cam 94 (FIG. 2) and roller 104 acting through cam 50, roller48 and spring 46(FIGS. 6 and 7), the folded envelope is delivered ontoendless conveyor belt 170 (FIG. 1) which passes around the pulley 174. Adeflecting member 172, which is fastened to the frame of the machineinsures delivery of the folded envelope onto the belt.

The paddles 110, 112, 114 and 116 are disposed about drum 34 so thatthere is a 45 angle between successive paddles. This enable the paddlesto keep the back portion of-the envelope tucked in while another fold isbeing made in the envelope.

The inner position of each paddleis about Vs inch from the periphery ofdrum 34; and the outer position is from inch to ,zinch from the drumperiphery.

The folded envelope may be carried by belt 170 beneath a labelingapparatus, such as disclosed in the U.S. Pat. of William L. Reineman,No. 3, 392,638issued Jul. 16,]968. This apparatus affixes a label 175(FIG. to the envelope to seal it folded. Thus it can be inserted into abox of roll film.

As the drum 34 continues to revolve the group of gripping bars 70, 36,36, 36, 36, which has just completed folding of an envelope rotates intoposition for the jaws 74 (FIG. 4) of bar 70 to grip a new envelopedelivered into the machine by belt 30, and the described foldingoperation begins anew on this new envelope. Meantime the other group ofgripping bars 70, 36, 36, 36, 36 is carrying another envelope around andit is being folded in the manner already described. Thus, with theillustrated mechanism folding operations on two envelopes can be carriedon simultaneously.

The various mechanisms can be actuated in timed relation in variousdifferent ways. FIG. 13 illustrates one way in which the several partsmay be geared together to effect their timed operations. Here the spuror helical gears of the drive are illustrated diagrammatically by theirpitch circles. 180 denotes the main drive gear, which may be driven by amotor or other suitable power source. This gear meshes with and drives agear 182 that is secured to shaft 95 (FIG. 1) coaxially thereof, todrive drum 34 and earns 120, 122, 124, 126 (FIG. 2). Gear 182 drives agear 184 that is secured to the shaft 186 which carries the scoring roll80 (FIG. 1). Gear 182 also meshes with and drives a gear 188 whichdrives gear 190 that is fixed to the shaft which carries the pulley 31that drives belt 30. Gear 190, intum, drives gear 192 on shaft 64 whichcarries cam 66. Gear 188 also drives a gear 194, which is an idler; andthis gear, in turn, drives gear 196 which is secured to shaft 198(FIG. 1) that carries the drive pulley 174 for belt 170. Thus, all theoperating parts may be actuated in proper timed relation.

Cams 120, 122, 124 and 126 are larger in diameter than cams 90, 91, 92,93, 94 (FIG. 2) to avoid interference of the shafts 156 with the bars 36and 70. The earns 90, 91, 92, 93, 94 may be removably mounted inperipheral grooves in sleeve 165 and may be split rings for quickremoval from or assembly to sleeve 165, or these cams may be formedintegral with projection 165; and projection 165 may be bolted orotherwise secured removably at one side of the frame 167 of the machine.Likewise, the cams 120, 122, 124, 126 may be split rings seated ingrooves in a cylinder 176 projecting laterally from the side of drum 34,or they may be integral with this cylinder; and the cylinder may bebolted or otherwise removably fixed to drum 34. Either constructionpermits quick change of cams fordifferent jobs, that is for foldingdifferent sizes and types of envelopes.

While the invention has been described in connection with a specificembodiment thereof, it will be understood then, that is it is capable offurther modification, and this application is intended to cover anyvariations, uses, or adaptions of the invention following, in general,the principles of the invention and including such departures from thepresent disclosure as come within known or customary practice in the artto which the invention pertains and as may be applied to the essentialfeatures hereinbefore set forth, and as fall within the scope of theinvention or the limits of the appended claims.

We claim: 7

1. A machine for folding envelopes, comprising:

a rotary drum,

a plurality of grippers carried by said drum for gripping an enveloperespectively at different points along the length of the envelope,

means for releasing said grippers successively as said drum revolves torelease successively different portions lengthwise of the envelope,

a plurality of folding members disposed about said drum,

and

means for moving said folding member successively to engage thesuccessively released portions of the envelope to fold said releaseportions successively upon one another and down on the unreleasedportion of the envelope.

2. A machine as claimed in claim 1, having additionally means disposedadjacent said drum for scoring an envelope, held by said grippers, atspaced points along its length before any portion of the envelope isreleased, to provide score lines along which the envelope issubsequently folded.

3. A machine as claimed in claim 2, wherein said scoring means comprisesa roll having a plurality of scoring blades spaced from one anotheraround its periphery,

the number of said blades being equal to the number of folds to be madein the envelope, and

means is provided for rotating said roll in time with the rotation ofsaid drum.

4. A machine as claimed in claim 1, wherein each of said gripperscomprises a bar having a rockable clamping member, and a cam andfollower are associated with each bar and are operatively connected tothe clamping member on the respective bar to move said clamping memberto and from operative position during rotation of said drum.

5. A machine as claimed in claim 4, wherein there are as many cams asthere are bars in a set of grippers for an envelope, and said cams arefixed relative to said drum so that said followers travel on said camsas the drum rotates.

6. A machine as claimed in claim 1, having a separate cam forcontrolling the movements of each folding member, and means for rotatingsaid separate cams in time with the rotation of said drum.

7. A machine as claimed in claim 4, having a separate cam forcontrolling the movements of each folding member, and means for rotatingsaid separate cams in time with said drum.

8. A machine for folding envelopes, comprising:

a rotary drum,

scoring means disposed adjacent said drum to score said envelope atspaced points along its length as the envelope is carried past saidscoring means by said drum in its rotation,

means for gripping an envelope at different points along the length ofthe envelope between score lines to clamp the envelope to the peripheryof said drum,

a plurality of folding members disposed adjacent said drum and spacedfrom one another around the periphery of said drum,

means for releasing different portions of said envelope successively asit approaches said successive folding members successively in therotation of said drum, and

means for moving said folding members successively into operativerelation with the successively released portions of said envelope tofold said released portions successively upon one another and upon theunreleased portion of the envelope.

9. A machine for folding envelopes comprising:

a rotary drum,

a plurality of gripper bars carried by said drum and spaced from oneanother around the periphery of said drum,

each gripper bar having thereon a pivoted clamping member for grippingan envelope and movable to and from operative positions,

a plurality of cams mounted coaxially with said drum to rotate therewithand operatively connected to the different clamping members to pivotsaid clamping members in opposite directions as said drum rotates, toeffect movement of the clamping members to and from operative positions,

a plurality of folding members disposed in angularly spaced relationabout said drum, and

a plurality of cams mounted coaxially with said drum to rotate therewithand operatively connected to the different folding members to move saidfolding members to and from operative position.

10. A machine as claimed in claim 9, wherein each folding member has anarcuate face confronting said drum.

11. A machine as claimed in claim 9, wherein said cams are so shapedthat when a portion of the envelope is released by a clamping member, afolding member is moved into operative position to engage the releasedportion of the envelope, whereby as the drum continues to rotate thereleased portion of the envelope is bent about a score line and iscarried under the folding member to be folded flat on the still-clampedportion of the envelope, and the preceding folding member remains inposition to hold the released portion of the envelope until it haspassed under the leading edge of the next succeeding folding member.

12. A machine for folding envelopes comprising:

a rotary drum,

a plurality of members for gripping an envelope at spaced points alongits length,

a plurality of spaced folding members disposed around said drums,

means for moving said gripping members to and from operative positionand effective to release said gripping members successively duringrotation of said drum to release successive portions of the envelopesuccessively, and

means for moving said folding members successively toward and away fromsaid drum during rotation of said drum to cause said folding members toengage the successively released portions of the envelope successivelyto fold the envelope on itself as the drum rotates.

13, A machine as claimed in claim '12, having:

means for feeding an envelope onto said drum for effecting folding ofthe envelope,

means for moving said gripping member first to released position toreceive the envelope and then to operative position to grip the envelopealong its length, and

wherein the foremost of said gripping members constitutes a stop tolocate the envelope precisely on the drum.

14. A machine as claimed in claim 13, having:

a rotary scoring member disposed adjacent said drum angularly in advanceof the first folding member, and

means for rotating said scoring member to impress score lines on saidenvelope along which it will be subsequently folded.

15. A machine as claimed in claim 12, wherein successive folding membersare spaced 45 away from each other around the periphery of said drum.

l A machine as claimed in claim 12, wherein the means for effectingmovement of the gripping members to released positions successivelycomprise a plurality of stationary earns.

17. A machine as claimed in claim 112, wherein: said folding members aremounted on a stationary part of the machine for movement toward and fromsaid drum in a direction generally radial of the axis of said drum, and

the means for moving said folding members comprises a plurality of cams,one for each folding member, and mounted to rotate in time with saiddrum.

18. A machine as claimed in claim 17, wherein said cams are mounted torotate with said drum.

19. A machine as claimed in claim 17, wherein the means for effectingmovement of the gripping members to released positions successivelycomprise a plurality of stationary cams mounted coaxially of said drum.

1. A machine for folding envelopes, comprising: a rotary drum, aplurality of grippers carried by said drum for gripping an enveloperespectively at different points along the length of the envelope, meansfor releasing said grippers successively as said drum revolves torelease successively different portions lengthwise of the envelope, aplurality of folding members disposed about said drum, and means formoving said folding member successively to engage the successivelyreleased portions of the envelope to fold said release portionssuccessively upon one another and down on the unreleased portion of theenvelope.
 2. A machine as claimed in claim 1, having additionally meansdisposed adjacent said drum for scoring an envelope, held by saidgrippers, at spaced points along its length before any portion of theenvelope is released, to provide score lines along which the envelope issubsequently folded.
 3. A machine as claimed in claim 2, wherein saidscoring means comprises a roll having a plurality of scoring bladesspaced from one another around its periphery, the number of said bladesbeing equal to the number of folds to be made in the envelope, and meansis provided for rotating said roll in time with the rotation of saiddrum.
 4. A machine as claimed in claim 1, wherein each of said gripperscomprises a bar having a rockable clamping member, and a cam andfollower are associated with each bar and are operatively connected tothe clamping member on the respective bar to move said clamping memberto and from operative position during rotation of said drum.
 5. Amachine as claimed in claim 4, wherein there are as many cams as thereare bars in a set of grippers for an envelope, and said cams are fixedrelative to said drum so that said followers travel on said cams as thedrum rotates.
 6. A machine as claimed in claim 1, having a separate camfor controlling the movements of each folding member, and means forrotating said separate cams in time with the rotation of said drum.
 7. Amachine as claimed in claim 4, having a separate cam for controlling themovements of each folding member, and means for rotating said separatecams in time with said drum.
 8. A machine for folding envelopes,comprising: a rotary drum, scoring means disposed adjacent said drum toscore said envelope at spaced points along its length as the envelope iscarried past said scoring means by said drum in its rotation, means forgripping an envelope at different points along the length of theenvelope between score lines to clamp the envelope to the periphery ofsaid drum, a plurality of folding members disposed adjacent said drumand spaced from one another around the periphery of said drum, means forreleasing different portions of said envelope successively as itapproaches said successive folding members successively in the rotationof said drum, and means for moving said folding members successivelyinto operative relation with the successively released portions of saidenvelope to fold said released portions successively upon one anotherand upon the unreleased portion of the envelope.
 9. A machine forfolding envelopes comprising: a rotary drum, a plurality of gripper barscarried by said drum and spaced from one another around the periphery ofsaid drum, each gripper bar having thereon a pivoted clamping member forgripping an envelope and movable to and from operative positions, aplurality of cams mounted coaxially with said drum to rotate therewithand operatively connected to the different clamping members to pivotsaid clamping members in opposite directions as said drum rotates, toeffect movement of the clamping members to and from operative positions,a plurality of folding members disposed in angularly spaced relationabout said drum, and a plurality of cams mounted coaxially with saiddrum to rotate therewith and operatively connected to the differentfolding members to move said folding members to and from operativeposition.
 10. A machine as claimed in claim 9, wherein each foldingmember has an arcuate face confronting said drum.
 11. A machine asclaimed in claim 9, wherein said cams are so shaped that when a portionof the envelope is released by a clamping member, a folding member ismoved into operative position to engage the released portion of theenvelope, whereby as the drum continues to rotate the released portionof the envelope is bent about a score line and is carried under thefolding member to be folded flat on the still-clamped portion of theenvelope, and the preceding folding member remains in position to holdthe released portion of the envelope until it has passed under theleading edge of the next succeeding folding member.
 12. A machine forfolding envelopes comprising: a rotary drum, a plurality of members forgripping an envelope at spaced points along its length, a plurality ofspaced folding members disposed around said drums, means for moving saidgripping members to and from operative position and effective to releasesaid gripping members successively during rotation of said drum torelease successive portions of the envelope successively, and means formoving said folding members successively toward and away from said drumduring rotation of said drum to cause said folding members to engage thesuccessively released portions of the envelope successively to fold theenvelope on itself as the drum rotates.
 13. A machine as claimed inclaim 12, having: means for feeding an envelope onto said drum foreffecting folding of the envelope, means for moving said gripping memberfirst to released position to receive the envelope and then to operativeposition to grip the envelope along its length, and wherein the foremostof said gripping members constitutes a stop to locate the envelopeprecisely on the drum.
 14. A machine as claimed in claim 13, having: arotary scoring member disposed adjacent said drum angularly in advanceof the first folding member, and means for rotating said scoring memberto impress score lines on said envelope along which it will besubsequently folded.
 15. A machine as claimed in claim 12, whereinsuccessive folding members are spaced 45* away from each other aroundthe periphery of said drum.
 16. A machine as claimed in claim 12,wherein the means for effecting movement of the gripping members toreleased positions successively comprise a plurality of stationary cams.17. A machine as claimed in claim 112, wherein: said folding members aremounted on a stationary part of the machine for movement toward and fromsaid drum in a direction generally radial of the axis of said drum, andthe means for moving said folding members comprises a plurality of cams,one for each folding member, and mounted to rotate in time with saiddrum.
 18. A machine as claimed in claim 17, wherein said cams aremounted to rotate with said drum.
 19. A machine as claimed in claim 17,wherein the means for effecting movement of the gripping members toreleased positions successively comprise a plurality of stationary camsmounted coaxially of said drum.